1. Technical Field
Embodiments of the present invention generally relate to a tandem image forming apparatus, such as a copier, a printer, a facsimile machine, or a multifunction peripheral having at least two of copying, printing, facsimile transmission, plotting, and scanning capabilities, and a waste-toner conveyance device to transport waste toner discharged from a cleaning device in a tandem image forming apparatus.
2. Description of the Related Art
There are tandem image forming apparatuses that include four image forming units to form yellow, magenta, cyan, and black toner images, respectively, transfer the respective color toner images, and superimpose the respective color toner images on a transfer medium such as an intermediate transfer member or a sheet of recording media such as paper, thereby obtaining full-color images. Such tandem image forming apparatuses can form full-color images using at least yellow, magenta, and cyan toners (and black toner as required) and monochrome images using black toner only.
In tandem image forming apparatuses, when one or more of the four colors is not used, for example, in monochrome image formation, the image forming units of colors not used may be disengaged from the transfer medium. For example, a sheet conveyance member to transport sheets of recording media is shaped into an endless belt, and the belt is moved away from the image forming units by moving a support roller supporting the belt. This configuration can reduce operation time of the image forming units not used, thereby extending operational lives thereof.
In tandem image forming apparatuses, toner images are formed on respective latent image bearers in the image forming units. After the toner images are transferred from the latent image bearers onto the transfer medium, a cleaning unit collects toner remaining thereon. The toner thus collected is discharged as waste toner from an outlet of the cleaning unit and transported by a waste-toner conveyance device to a waste-toner container.